1. Field
Example embodiments relate to a Poly-Si thin film transistor (TFT) using Poly-Si as a channel material and a method of manufacturing the Poly-Si TFT.
2. Description of the Related Art
Poly-Si TFTs using Poly-Si as a channel material may be employed in panels of active matrix liquid crystal display devices (AMLCD) or active matrix organic light emitting display devices (AMOLED) due to their higher mobility. However, a process for manufacturing the Poly-Si TFTs may be complicated, and when Poly-Si are formed using a laser, applying the Poly-Si TFTs to large-sized panels may be difficult because of non-uniformity due to laser crystallization. In order to solve such problems, research has been conducted to manufacture a Poly-Si TFT by crystallizing amorphous silicon (a-Si) in a furnace without using a laser.
TFTs may be classified, based on their structure, into top gate structure types and bottom gate structure types depending on a location of a gate. The top gate structure may be applied to mass production of a Poly-Si TFT, and the bottom gate structure may be generally applied to mass production of an amorphous silicon TFT. Manufacturing the bottom gate structure requires a relatively small number of processes, and thus, the bottom gate structure may be more advantageous in cost reduction than the top gate structure. On the other hand, Poly-Si TFTs need to employ a lightly doped drain (LDD) structure in order to reduce leakage current, but in order to employ the LDD structure, a photolithography process and an ion implantation process may be additionally required.